1. Field of the Invention
The present invention relates to prosthetics, and more specifically, it relates to an adjusting mechanism for a prosthetic.
2. Description of Related Art
A variety of adjustable prosthesis joints are known; however, they are generally expensive to manufacture, complex and larger than desirable.
For example, U.S. Pat. No. 5,957,981 claims an adjustable prosthesis joint to set the angular relation between an attachment socket for connecting the joint to a cooperating body member and a prosthesis detail, the prosthesis joint comprising a housing; a chamber disposed in the housing; an intermediate wall fixed within the chamber to subdivide the chamber into at least two communicating chamber portions, wherein the cross-section of the chamber is curved so that the wall subdivides the chamber into two cylindrical curved chamber portions; an adjustable valve provided in a valve housing in connection to the wall, wherein the adjustable valve is movable between a closed position and an open position; a flow medium to communicate between the chamber portions through the valve; at least two pistons wherein each piston is movably disposed in one of the two chamber portions and the pistons are interconnected to and are adapted to be uniformly displaced in relation to the wall under flow of the flow medium through the valve in the open position between the chambers.
Another example of a prostheses joint that is complex, expensive to manufacture and large is found in U.S. Pat. No. 5,704,945, which claims a brake-action knee joint for a leg prosthesis, comprising: an upper prosthetic part; a lower prosthetic part; a joint pin which includes a rotary piston and which is connected in a torsionally rigid fashion to the upper part of the joint; a rocker which forms a central part of the joint, the rocker having an extension-side end fixed to a rocker pin lying parallel, ventrally and distally with respect to the joint pin and having a flexion-side end, wherein the rocker surrounds the joint pin; and a braking device activated by foot loading, which includes a closed, fluid-filled displacer chamber; a valve plunger having an open position and a closed position; a valve-plunger spring; and a first adjusting device mounted on the lower prosthetic part of the joint and connected to the valve plunger; wherein the displacer chamber concentrically surrounds the joint pin over its circumference, at least partially and is arranged in an associated end of the central part of the joint, wherein the rotary piston divides the displacer chamber into an extension chamber and a flexion chamber, which are connected to one another by way of an oil line which can be completely or partially closed by the valve plunger; and wherein the valve plunger is mounted in the central part of the joint in such a way as to be displaceable counter to the action of the valve-plunger spring pushing it into its open position and, when the central part of the joint is pivoted in the direction of flexion about the rocker pin, is pushed into its closed position by the adjusting device.
It is desirable to provide a simplified, relatively inexpensive and small mechanism for adjusting the angular position of a prosthetic. The present invention provides such a mechanism.